package com.atguigu.gulimall.product.web;

import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;
import com.atguigu.gulimall.product.vo.Catelog2Vo;
import org.redisson.api.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantReadWriteLock;

@Controller
public class IndexController {

    @Autowired
    private CategoryService categoryService;
    @Autowired
    private RedissonClient redisson;
    @Autowired
    private StringRedisTemplate redisTemplate;

    @GetMapping({"/", "/index.html"})
    public String indexPage(Model model) {
        // TODO 1、查出所有级分类
        List<CategoryEntity> categoryEntities = categoryService.getLevel1Categorys();

        // 视图解析器进行拼串
        // 默认前缀  classpath:/templates/   ； 默认后缀  .html
        model.addAttribute("categorys", categoryEntities);
        return "index";
    }


    //    index/catalog.json
    @ResponseBody
    @GetMapping({"/index/catalog.json"})
    public Map<String, List<Catelog2Vo>> getCatalogJson(Model model) {

        Map<String, List<Catelog2Vo>> map = categoryService.getCatalogJson();

        return map;
    }

    //    index/catalog.json
    @ResponseBody
    @GetMapping({"/hello"})
    public String hello() {
        // 1、获取一把锁，只要锁的名字一样，就是同一把锁
        RLock lock = redisson.getLock("my-lock");

        // 2、加锁
//        lock.lock();//阻塞式等待，默认的加锁时间是30s
        // 1）、锁的自动续期，如果业务超长，运行期间自动给锁续上新的30s。不用担心业务时间长，锁自动过期被删掉
        // 2）、加锁的业务只要运行完成，就不会给当前锁续期，即使不手动解锁，锁默认在30s后自动删除

        lock.lock(10, TimeUnit.SECONDS);//10s后自动解锁
        // 问题lock.lock(10, TimeUnit.SECONDS);在锁时间到了以后，不会自动续期
        // 1、如果我们传递了锁的时间，就发送给redis执行脚本，进行占锁，默认超时就是我们指定的时间
        // 2、如果我们未指定锁的超市时间，就使用 30 * 1000【LockWatchdogTimeout看门狗的默认时间】；
        //      只要占锁成功，九所启动一个定时任务【重新给锁设置过期时间，新的过期时间就是看门狗的默认时间】，每隔10s都会再次续期，续成30s
        //      internalLockLeaseTime【看门狗时间】 / 3L

        // 最佳实战
        // 1）、lock.lock(10, TimeUnit.SECONDS);省掉了整个续期操作。手动解锁
        try {
            System.out.println("加锁成功，执行业务..." + Thread.currentThread().getId());
            Thread.sleep(30000);
        } catch (Exception e) {

        } finally {
            // 3、解锁  假设解锁代码没有运行，redisson会不会出现死锁
            System.out.println("释放锁..." + Thread.currentThread().getId());
            lock.unlock();
        }

        return "hello";
    }

    // 保证一定能读到最新数据，修改期间，写锁是一个排他锁（互斥锁、独享锁）。读锁是一个共享锁、
    // 写锁没释放读就必须等待
    // 写 + 读：等待写锁释放
    // 写 + 写：阻塞方式
    // 读 + 写：有读锁，写也需要等待
    // 读 + 读：相当于无锁，只会在redis中记录好，所有当前的读锁，都会同时加锁成功
    @ResponseBody
    @GetMapping({"/write"})
    public String writeValue() {
        RReadWriteLock lock = redisson.getReadWriteLock("rw-lock");
        String s = "";
        RLock rLock = lock.writeLock();
        try {
            //1、改数据加写锁，读数据加读锁
            rLock.lock();
            System.out.println("写锁加锁成功..." + Thread.currentThread().getId());
            s = UUID.randomUUID().toString();
            Thread.sleep(30000);
            redisTemplate.opsForValue().set("writeValue", s);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            rLock.unlock();
            System.out.println("写锁释放" + Thread.currentThread().getId());
        }
        return s;
    }

    @ResponseBody
    @GetMapping({"/read"})
    public String readValue() {
        RReadWriteLock lock = redisson.getReadWriteLock("rw-lock");
//        ReentrantReadWriteLock reentrantReadWriteLock = new ReentrantReadWriteLock();
        String s = "";
        // 加读锁
        RLock rLock = lock.readLock();
        rLock.lock();
        try {
            System.out.println("读锁加锁成功" + Thread.currentThread().getId());
            s = redisTemplate.opsForValue().get("writeValue");
            Thread.sleep(30000);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            rLock.unlock();
            System.out.println("读锁释放" + Thread.currentThread().getId());
        }
        return s;
    }

    /**
     * 放假 锁门
     * 1班没人 2班..
     * 等到5个班都走完，就可以锁大门
     */
    @ResponseBody
    @GetMapping({"/lockDoor"})
    public String lockDoor() throws InterruptedException {
        RCountDownLatch door = redisson.getCountDownLatch("door");
        door.trySetCount(5);
        door.await();// 等待闭锁都完成
        return "放假了...";
    }


    @ResponseBody
    @GetMapping({"/gogogo/{id}"})
    public String go(@PathVariable("id") Long id) {
        RCountDownLatch door = redisson.getCountDownLatch("door");
        door.countDown();// 计数减一
        return id + "班的人走了";
    }

    /**
     * 车库停车
     * 信号量也可以用作分布式限流
     *
     * @return
     * @throws InterruptedException
     */
    @ResponseBody
    @GetMapping({"/park"})
    public String park() throws InterruptedException {
        RSemaphore park = redisson.getSemaphore("park");
//        park.acquire();// 获取一个信号，获取一个值，使用车位
        boolean b = park.tryAcquire();// 尝试获取一个信号
        if (b) {
            // 执行业务
        } else {
            return "error";
        }
        return "ok=>" + b;
    }

    @ResponseBody
    @GetMapping({"/go"})
    public String go() throws InterruptedException {
        RSemaphore park = redisson.getSemaphore("park");
        park.release();// 释放车位

        return "ok";
    }
}
